R-36 (missile) - R-36M (SS-18) Variants

R-36M (SS-18) Variants

• R-36M (SS-18 Mod 1): The SS-18 Mod 1 carried a single large reentry vehicle, with a warhead yield of 18-25 MT, a distance of about 6000 nm. In January 1971, cold-launch tests began during which the mortar launch was perfected. The actual flight tests for the single-RV Mod 1 began on 21 February 1973, though some sources suggest that testing began in October 1972. The testing phase of the R-36M with various different types of warheads was finished in October 1975 and on 30 December 1975 deployment began (though some Western sources suggest that an initial operational capability was reached in early 1975). A total of 56 were deployed by 1977, though all were replaced by Mod 3 or Mod 4 missiles by 1984. These high-yield weapons were assessed in the West as possibly developed to attack American Minuteman ICBM launch control centers. Tom Clancy described this potential tasking as the ability to 'turn Cheyenne Mountain into Cheyenne Lake.'

• R-36M (SS-18 Mod 2): The SS-18 Mod 2 included a post-boost vehicle and up to eight reentry vehicles, each with a warhead yield estimated at between 0.5 to 1.5 MT, with a range capability of about 5500 nm. The MIRVs were placed in pairs, and a post boost vehicle with a command structure and a propulsion system were contained in the nose cone of the R-36M. The flight tests of the MIRVed Mod 2 began in September 1973 (though some Western sources suggest that the initial flight test of the Mod 2 MIRV version occurred in August 1973), with IOC in 1975. Approximately 132 were deployed by 1978, but the post-boost vehicle design was seriously flawed, and the Mod 2 missiles were all replaced by the Mod 4 variant by 1983.

• R-36M (SS-18 Mod 3): The SS-18 Mod 3 carried a single large reentry vehicle that was an improved version of the SS-18 Mod 1. On 16 August 1976, a few months after the R-36M entered service, the development of an improved modification of the R-36M (15A14) was approved. This missile subsequently received the designation R-36MUTTh (15A18) and was developed by KB Yuzhnoye (OKB-586) through December 1976. The R-36MUTTh was capable of carrying two different nose cones. On 29 November 1979, deployment of the improved R-36M with a single reentry vehicle carrying a 18-25 MT warhead (SS-18 Mod 3) began.

• R-36MUTTh (SS-18 Mod 4): The SS-18 Mod 4 was probably designed to attack and destroy ICBMs and other hardened targets in the US. Its increasing accuracy made it possible to reduce the yield of the warheads and allowed an increase in the number of warheads from 8 to 10. According to some Western estimates, evidence suggested that the Mod 4 may be capable of carrying as many as 14 RVs (this may reflect observation of the deployment of countermeasures intended to overcome a ballistic missile defense, or to confuse American attack characterization systems). The flight-design tests of the R-36MUTTh began on 31 October 1977 and in November 1979 the flight tests of the MIRVed missile were completed. The first three regiments were put on alert on 18 September 1979. During 1980 a total of 120 SS-18 Mod 4 missiles were deployed, replacing the last remaining R-36 (SS-9) missiles. In 1982–1983 the remaining R-36M missiles were also replaced with the new R-36MUTTh and the total number of deployed missiles reached the maximum 308 ceiling established in the SALT-1 treaty. The SS-18 Mod 4 force had the estimated capability to destroy 65 to 80 percent of US ICBM silos using two nuclear warheads against each. Even after this type of attack, it was estimated that more than 1000 SS-18 warheads would be available for further strikes against targets in the US. After 2009, the SS-18 Mod 4s were all eliminated in favor of the newer SS-18 Mod 5.

• R-36M2 Voivode (SS-18 Mod 5): The newer, more accurate SS-18 Mod 5 version placed in converted silos allowed the SS-18 to remain the bulwark of the SRF's hard-target-kill capability. The Mod 5 carries 10 MIRVs, each having a higher yield than the Mod 4 warheads. The Mod 5 warheads have nearly twice the yield of the Mod 4 (approximately 750 KT to 1 MT) according to Western estimates, though Russian sources suggest a yield of 550-750 KT each. The increase in the Mod 5's warhead yield, along with improved accuracy, would, under the START treaty, help allow the Russians to maintain their hard-target-kill wartime requirements even with the 50 percent cut in heavy ICBMs the START agreement required. The technical proposals to build a modernized heavy ICBM were made in June 1979. The missile subsequently received the designation R-36M2 Voivode and the industrial index number 15A18M. The design of the R-36 M2 Voivode was completed in June 1982. The R-36M2 consisted of a series of new engineering features. The engine of the second stage is completely built in the fuel tank (earlier this was only used on SLBMs) and the design of the transport-launching canister was altered. Unlike the R-36M, the 10 warheads on the post-boost vehicle are located on a special frame in two circles. The flight tests of the R-36M2 equipped with 10 MIRVs began in March 1986 and were completed in March 1988. The first regiment with these missiles was put on alert on 30 July 1988 and was deployed on 11 August 1988.

• R-36M2 Voivode (SS-18 Mod 6): The flight tests of the R-36M2 missile carrying a single warhead (SS-18 Mod 6) with a yield of 20 MT were completed in September 1989 and deployment began in August 1991. Ten Mod 6 missiles were deployed. One intended use of these large warheads was high altitude detonation to incapacitate electronics and communications through a very large electromagnetic pulse. The SS-18 Mod 6 missiles were all decommissioned by late 2009.

At full deployment, before the fall of the Soviet Union in 1991, 308 SS-18 launch silos were operational. After the breakup of the USSR, 204 of these were located on the territory of the Russian Federation and 104 on the territory of newly independent Kazakhstan. The dismantling of 104 launchers located in Kazakhstan was completed in September 1996. The START II treaty was to eliminate all SS-18 missiles but it did not enter into force and the missiles remained on duty. Russia has steadily decreased the number of operational SS-18s and by July 2009, only 59 (all of the 10 MIRV Mod 5 version) remain. About 40 missiles will have their service lives extended so that they remain in service until about 2020. With the retirement of the 20 megaton SS-18 Mod 6 warheads, the highest yield weapon in service with any nation is the estimated 5 MT Chinese Dong Feng 5 (DF-5) ICBM (CSS-4) warhead.

All R-36 variants were designed to be launched from silos in dispersed and hardened locations. The R-36M is placed into its 39 m deep silo in a tubular storage/launch container. Upon launch the missile is shot out of the tube, mortar-fashion, by a piston, driven by the expansion of gases from a slow-burning black powder charge inside the piston. The missile's main engine is ignited tens of metres above the ground, preventing any damage to the internal equipment of the silo itself from the rocket engine's fiery efflux.